kpd: add optional mirror support

We always clone a full repository. This is counter productive and
wasteful. Allow users to specify that they are using kpd to help
test patches for a git tree which we should expect a mirror on
a target mirror path. We simply check for a mirror for you git tree
and if present we use it.

So for example, all kdevops enterprise deployments can easily
profit from this as kdevops has support to mirror all target git
trees it supports under /mirror/ through an NFS export for clients.
And so small thing guests can be used for kpd instances, which
can leverage this NFS export.

This allows kpd to be run on smaller guests with less storage needs.
This should allow more than one kpd instance to run on small guests
too.

Generated-by: Claude AI
Signed-off-by: Luis Chamberlain <[email protected]>
Signed-off-by: Daniel Gomez <[email protected]>

Author: dkruces

configs/kpd.json

@@ -30,16 +30,19 @@
       "upstream_branch": "master",
       "ci_repo": "https://github.com/kernel-patches/vmtest.git",
       "ci_branch": "master",
-      "github_oauth_token": "<TOKEN>"
+      "github_oauth_token": "<TOKEN>",
+      "mirror_fallback_repo": "linux.git"
     },
     "bpf": {
       "repo": "https://github.com/kernel-patches/bpf",
       "upstream": "https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git",
       "upstream_branch": "master",
       "ci_repo": "https://github.com/kernel-patches/vmtest.git",
       "ci_branch": "master",
-      "github_oauth_token": "<TOKEN>"
+      "github_oauth_token": "<TOKEN>",
+      "mirror_fallback_repo": "linux.git"
     }
   },
-  "base_directory": "/tmp/repos"
+  "base_directory": "/tmp/repos",
+  "mirror_dir": "/mirror/"
 }

kernel_patches_daemon/branch_worker.py

@@ -547,6 +547,8 @@ def __init__(
         app_auth: Optional[Auth.AppInstallationAuth] = None,
         email: Optional[EmailConfig] = None,
         http_retries: Optional[int] = None,
+        mirror_fallback_repo: Optional[str] = None,
+        mirror_dir: Optional[str] = None,
     ) -> None:
         super().__init__(
             repo_url=repo_url,
@@ -559,6 +561,8 @@ def __init__(
         self.email = email
 
         self.log_extractor = log_extractor
+        self.mirror_dir = mirror_dir
+        self.mirror_fallback_repo = mirror_fallback_repo
         self.ci_repo_url = ci_repo_url
         self.ci_repo_dir = _uniq_tmp_folder(ci_repo_url, ci_branch, base_directory)
         self.ci_branch = ci_branch
@@ -682,9 +686,27 @@ def do_sync(self) -> None:
     def full_sync(self, path: str, url: str, branch: str) -> git.Repo:
         logging.info(f"Doing full clone from {redact_url(url)}, branch: {branch}")
 
+        multi_opts: Optional[List[str]] = None
+        if self.mirror_dir:
+            upstream_name = os.path.basename(self.upstream_url)
+            reference_path = os.path.join(self.mirror_dir, upstream_name)
+
+            # If primary mirror doesn't exist, try fallback path
+            if not os.path.exists(reference_path) and self.mirror_fallback_repo:
+                fallback_path = os.path.join(self.mirror_dir, self.mirror_fallback_repo)
+                if os.path.exists(fallback_path):
+                    reference_path = fallback_path
+
+            # Use --reference-if-able when mirror path exists
+            if os.path.exists(reference_path):
+                multi_opts = ["--reference-if-able", reference_path]
+
         with HistogramMetricTimer(git_clone_duration, {"branch": branch}):
             shutil.rmtree(path, ignore_errors=True)
-            repo = git.Repo.clone_from(url, path)
+            if multi_opts:
+                repo = git.Repo.clone_from(url, path, multi_options=multi_opts)
+            else:
+                repo = git.Repo.clone_from(url, path)
             _reset_repo(repo, f"origin/{branch}")
 
         git_clone_counter.add(1, {"branch": branch})

kernel_patches_daemon/config.py

@@ -83,6 +83,7 @@ class BranchConfig:
     ci_branch: str
     github_oauth_token: Optional[str]
     github_app_auth: Optional[GithubAppAuthConfig]
+    mirror_fallback_repo: Optional[str] = None
 
     @classmethod
     def from_json(cls, json: Dict) -> "BranchConfig":
@@ -101,6 +102,7 @@ def from_json(cls, json: Dict) -> "BranchConfig":
             ci_branch=json["ci_branch"],
             github_oauth_token=json.get("github_oauth_token", None),
             github_app_auth=github_app_auth_config,
+            mirror_fallback_repo=json.get("mirror_fallback_repo", None),
         )
 
 
@@ -171,6 +173,7 @@ class KPDConfig:
     branches: Dict[str, BranchConfig]
     tag_to_branch_mapping: Dict[str, List[str]]
     base_directory: str
+    mirror_dir: Optional[str] = None
 
     @classmethod
     def from_json(cls, json: Dict) -> "KPDConfig":
@@ -203,6 +206,7 @@ def from_json(cls, json: Dict) -> "KPDConfig":
                 for name, json_config in json["branches"].items()
             },
             base_directory=json["base_directory"],
+            mirror_dir=json.get("mirror_dir"),
         )
 
     @classmethod

kernel_patches_daemon/github_sync.py

@@ -114,6 +114,8 @@ def __init__(
                 ci_branch=branch_config.ci_branch,
                 log_extractor=_log_extractor_from_project(kpd_config.patchwork.project),
                 base_directory=kpd_config.base_directory,
+                mirror_dir=kpd_config.mirror_dir,
+                mirror_fallback_repo=branch_config.mirror_fallback_repo,
                 http_retries=http_retries,
                 github_oauth_token=branch_config.github_oauth_token,
                 app_auth=github_app_auth_from_branch_config(branch_config),

tests/test_branch_worker.py

@@ -68,6 +68,7 @@
 TEST_CI_REPO_URL = f"https://user:[email protected]/ci-org/{TEST_CI_REPO}"
 TEST_CI_BRANCH = "test_ci_branch"
 TEST_BASE_DIRECTORY = "/repos"
+TEST_MIRROR_DIRECTORY = "/mirror"
 TEST_BRANCH = "test-branch"
 TEST_CONFIG: Dict[str, Any] = {
     "version": 2,
@@ -124,6 +125,8 @@ def __init__(self, *args: Any, **kwargs: Any) -> None:
             "ci_branch": TEST_CI_BRANCH,
             "log_extractor": DefaultGithubLogExtractor(),
             "base_directory": TEST_BASE_DIRECTORY,
+            "mirror_dir": None,
+            "mirror_fallback_repo": None,
         }
         presets.update(kwargs)
 
@@ -464,6 +467,69 @@ def test_fetch_repo_path_exists_git_exception(self) -> None:
             self._bw.fetch_repo(*fetch_params)
             fr.assert_called_once_with(*fetch_params)
 
+    def test_full_sync_with_mirror_dir(self) -> None:
+        bw = BranchWorkerMock(mirror_dir=TEST_MIRROR_DIRECTORY)
+        mirror_path = os.path.join(
+            TEST_MIRROR_DIRECTORY, os.path.basename(TEST_UPSTREAM_REPO_URL)
+        )
+        with (
+            patch("kernel_patches_daemon.branch_worker.os.path.exists") as exists,
+            patch("kernel_patches_daemon.branch_worker.shutil.rmtree") as rm,
+        ):
+            exists.side_effect = lambda p: p == mirror_path
+            bw.upstream_url = TEST_UPSTREAM_REPO_URL
+            bw.full_sync("somepath", "giturl", "branch")
+            self._git_repo_mock.clone_from.assert_called_once_with(
+                "giturl",
+                "somepath",
+                multi_options=["--reference-if-able", mirror_path],
+            )
+
+    def test_full_sync_with_mirror_fallback_repo(self) -> None:
+        fallback_repo = "linux.git"
+        bw = BranchWorkerMock(
+            mirror_dir=TEST_MIRROR_DIRECTORY, mirror_fallback_repo=fallback_repo
+        )
+        primary_mirror_path = os.path.join(
+            TEST_MIRROR_DIRECTORY, os.path.basename(TEST_UPSTREAM_REPO_URL)
+        )
+        fallback_mirror_path = os.path.join(TEST_MIRROR_DIRECTORY, fallback_repo)
+        with (
+            patch("kernel_patches_daemon.branch_worker.os.path.exists") as exists,
+            patch("kernel_patches_daemon.branch_worker.shutil.rmtree") as rm,
+        ):
+            # Primary mirror doesn't exist, but fallback does
+            exists.side_effect = lambda p: p == fallback_mirror_path
+            bw.upstream_url = TEST_UPSTREAM_REPO_URL
+            bw.full_sync("somepath", "giturl", "branch")
+            # Should use fallback mirror path for reference
+            self._git_repo_mock.clone_from.assert_called_once_with(
+                "giturl",
+                "somepath",
+                multi_options=["--reference-if-able", fallback_mirror_path],
+            )
+
+    def test_full_sync_without_mirror_fallback_repo(self) -> None:
+        bw = BranchWorkerMock(
+            mirror_dir=TEST_MIRROR_DIRECTORY, mirror_fallback_repo=None
+        )
+        mirror_path = os.path.join(
+            TEST_MIRROR_DIRECTORY, os.path.basename(TEST_UPSTREAM_REPO_URL)
+        )
+        with (
+            patch("kernel_patches_daemon.branch_worker.os.path.exists") as exists,
+            patch("kernel_patches_daemon.branch_worker.shutil.rmtree") as rm,
+        ):
+            # Mirror doesn't exist, and no fallback repo specified - should not use reference
+            exists.side_effect = lambda p: False
+            bw.upstream_url = TEST_UPSTREAM_REPO_URL
+            bw.full_sync("somepath", "giturl", "branch")
+            # Should clone without reference
+            self._git_repo_mock.clone_from.assert_called_once_with(
+                "giturl",
+                "somepath",
+            )
+
     def test_expire_branches(self) -> None:
         """Only the branch that matches pattern and is expired should be deleted"""
         not_expired_time = datetime.fromtimestamp(3 * BRANCH_TTL)

tests/test_config.py

@@ -205,8 +205,19 @@ def test_valid(self) -> None:
                     ci_branch="ci_branch",
                     github_app_auth=None,
                     github_oauth_token="TEST_OAUTH_TOKEN",
+                    mirror_fallback_repo=None,
                 ),
             },
             base_directory="/repos",
+            mirror_dir=None,
         )
         self.assertEqual(config, expected_config)
+
+    def test_branch_mirror_fallback_repo(self) -> None:
+        kpd_config_json = read_fixture("fixtures/kpd_config.json")
+        kpd_config_json["branches"]["oauth"]["mirror_fallback_repo"] = "linux.git"
+
+        with patch("builtins.open", mock_open(read_data="TEST_KEY_FILE_CONTENT")):
+            config = KPDConfig.from_json(kpd_config_json)
+
+        self.assertEqual(config.branches["oauth"].mirror_fallback_repo, "linux.git")

tests/test_github_sync.py

@@ -126,6 +126,20 @@ class TestCase:
                     gh.workers[TEST_BRANCH].ci_repo_dir.startswith(case.prefix),
                 )
 
+    def test_init_with_mirror_dir(self) -> None:
+        config = copy.copy(TEST_CONFIG)
+        config["mirror_dir"] = "/mirror"
+        kpd_config = KPDConfig.from_json(config)
+        gh = GithubSyncMock(kpd_config=kpd_config)
+        self.assertEqual("/mirror", gh.workers[TEST_BRANCH].mirror_dir)
+
+    def test_init_with_mirror_fallback_repo(self) -> None:
+        config = copy.copy(TEST_CONFIG)
+        config["branches"][TEST_BRANCH]["mirror_fallback_repo"] = "linux.git"
+        kpd_config = KPDConfig.from_json(config)
+        gh = GithubSyncMock(kpd_config=kpd_config)
+        self.assertEqual("linux.git", gh.workers[TEST_BRANCH].mirror_fallback_repo)
+
     def test_close_existing_prs_for_series(self) -> None:
         matching_pr_mock = MagicMock()
         matching_pr_mock.title = "matching"